/Engine/Plugins/FX/Niagara/Source/Niagara/Classes/NiagaraDataInterface.h
Generate the necessary plumbing HLSL at the end of the stage where this is used as a sim stage iteration source. Note that this should inject other internal calls using the CustomHLSL node syntax. See GridCollection2D for an example.
virtual bool GenerateIterationSourceNamespaceWriteAttributesHLSL ( [FNiagaraDataInterfaceGPUParamInfo](API\Plugins\NiagaraShader\FNiagaraDataInterfaceGPUParamInf-) & DIInstanceInfo, const [FNiagaraVariable](API\Plugins\Niagara\FNiagaraVariable) & InIterationSourceVariable, TConstArrayView< [FNiagaraVariable](API\Plugins\Niagara\FNiagaraVariable) > InArguments, TConstArrayView< [FNiagaraVariable](API\Plugins\Niagara\FNiagaraVariable) > InAttributes, TConstArrayView< [FString](API\Runtime\Core\Containers\FString) > InAttributeHLSLNames, TConstArrayView< [FNiagaraVariable](API\Plugins\Niagara\FNiagaraVariable) > InAllAttributes, bool bSpawnOnly, bool bPartialWrites, [TArray](API\Runtime\Core\Containers\TArray)< [FText](API\Runtime\Core\Internationalization\FText) > & OutErrors, [FString](API\Runtime\Core\Containers\FString) & OutHLSL ) const